diff --git a/src/soap/soapy/kernel.py b/src/soap/soapy/kernel.py
index 00ec46a1be2d77f39902cf34a379da618b7b70f5..a7ffff71b4541f73f794a87a7f4e611ff74d8fc1 100644
--- a/src/soap/soapy/kernel.py
+++ b/src/soap/soapy/kernel.py
@@ -395,7 +395,7 @@ class KernelAdaptorSpecific(object):
         self.S = len(types_global)
         return
     def adapt(self, spectrum):
-        IX = np.zeros((0.,0.), dtype='float64')
+        IX = np.zeros((0,0), dtype='float64')
         dimX = -1
         for atomic_i in spectrum:
             Xi_unnorm, Xi_norm = self.adaptScalar(atomic_i)